DAY

The Celtic and Gaelic word deag or dagh signifies good, excellent, the same as Da, in Welsh. Camden supposes the name to be a contraction of David. Dai, Du, in the Welsh, signifies dark, in allusion to the complexion or color of the hair. Dhu, in Gaelic, the same, dark color, black. Deah, Anglo-Saxon, dark, obscure.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.

DAY. 1. See David. 2. A tradition states that a follower of the Conqueror settled at Eye in Suffolk, and assumed therefrom the name of D'Eye or Deye.

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.